readAheadLimit - Limit on the number of characters that may be
read while still preserving the mark. Because
the stream's input comes from a character array,
there is no actual limit; hence this argument is
ignored.

close

public void close()

Closes the stream and releases any system resources associated with
it. Once the stream has been closed, further read(), ready(),
mark(), reset(), or skip() invocations will throw an IOException.
Closing a previously closed stream has no effect.